IV SAGE - Semana Acadêmica da Geofísica Espacial

5 Oct 2026, 08:00 → 9 Oct 2026, 20:30 America/Sao_Paulo

IAI (INPE)

Jayne Alencar de Melo (Instituto Nacional de Geofísica Espacial), Jose Marchezi (National Institute for Space Research - INPE), vinicius deggeroni (INPE)

É com muita satisfação que estamos realizando a IV Semana Acadêmica da Geofísica Espacial (SAGE-INPE). O evento ocorrerá no Instituto Nacional de Pesquisas Espaciais (INPE), na Divisão de Heliofísica, Ciências Planetárias e Aeronomia (DIHPA), de 05 a 09 de outubro de 2026, conforme programação divulgada.

A SAGE-INPE visa:

• Promover conhecimento na área de Heliofísica, Geofísica Espacial e Aeronomia;
• Fortalecer e integrar a comunidade científica em Heliofísica e Geofísica Espacial;
• Incentivar a integração entre alunos e pesquisadores da pós-graduação em Geofísica Espacial;
• Consolidar um ambiente de troca acadêmica, colaboração científica e formação de novos pesquisadores.

As atividades programadas para a SAGE-INPE envolverão a apresentação de trabalhos dos inscritos, especialmente de alunos da PGGES, palestras e seminários com pesquisadores convidados, cerimônia para os formandos de 2025/2026, visitas técnicas (VAGAS ESGOTADAS) e atividades de integração acadêmica.

Nesta edição, a SAGE será um evento aberto para alunos e pesquisadores da área de Geofísica Espacial de qualquer instituição.

Organização SAGE:

Jayne Alencar de Melo
Jose Paulo Marchezi
Jaziel Felipe Braga Campelo
Hadassa Raquel Peixoto Jácome
Vinicius Deggeroni
Emily Silva Rosa
Femi Olajide-Owoyomi
Daniele da Silva Ferreira Medeiros
Bruno Fernandes Garcia
Edu Pacheco Rockenbach
Caroline Monteiro Botelho
Karen Júlia Coldebella Ferreira
Érik Antunes Barbosa
Alexsander de Souza Pires
Suallyson Sômston Araújo da Cruz
Marlos Rockenbach da Silva
Alisson Dal Lago

 

Realização:

 

 

Apoio:

Monday 5 October

Badge pickup | Entrega de Crachá

Openning | Abertura

Abertura da semana acadêmica

Conveners: Bruno Fernandes Garcia, Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

Invited Talk | Palestra Convidada

Conveners: Bruno Fernandes Garcia, Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

1 Ionospheric Remote Sensing Using Satellite Data: Applications to Space Weather

The ionosphere is a highly dynamic region of the upper atmosphere where variations in plasma density are driven by a variety of processes, particularly solar radiation, geomagnetic activity, atmospheric waves, and electrodynamic mechanisms. These variations can significantly affect the propagation of radio signals and the performance of technologies that rely on them, making ionospheric monitoring an important component of space weather research. Today, ground-based Global Navigation Satellite System (GNSS) networks, in situ satellite measurements, and radio occultation observations provide complementary perspectives of the ionosphere across different spatial and temporal scales. This presentation provides an overview of how GNSS and satellite observations can be used to remotely sense the ionosphere and investigate its response to different space weather conditions. Ground-based GNSS measurements will be introduced as a powerful tool for mapping the spatial and temporal evolution of ionospheric electron density and identifying plasma structures and irregularities through parameters such as total electron content (TEC), ROTI, detrended TEC, SIDX, and amplitude scintillation (S4). These observations will be complemented by measurements from low-Earth-orbit satellites, including Swarm observations of electron density, plasma density irregularities, and topside TEC, as well as COSMIC radio occultation measurements that provide vertical electron density profiles and information about the three-dimensional structure of the ionosphere. Using selected observational examples, we will explore how these complementary datasets can be combined to investigate important ionospheric phenomena, including equatorial plasma bubbles, traveling ionospheric disturbances, geomagnetic storm responses, and ionospheric effects associated with solar flares. Particular emphasis will be placed on understanding what each observing technique measures, its advantages and limitations, and how combining observations from the ground and space provides a more complete picture of ionospheric dynamics. The presentation aims to provide students with a practical introduction to modern ionospheric remote sensing and its applications to space weather research.

Speaker: Giorgio Picanço (Space Science Laboratory, University of Massachusetts Lowell, USA)

Invited Talk | Palestra Convidada: Pos graduação GEO

Conveners: Bruno Fernandes Garcia, Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

2 Estagio no exterior

10:45 Coffee Break

Oral Presentations | Apresetações Orais: Sessão 2

Apresentação dos Alunos

Conveners: Bruno Fernandes Garcia, Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

3 Effects of the very weak geomagnetic storm of 15 April 2025 and intense storm of 16 April 2025 in the low-latitude and equatorial ionosphere over Brazil

R. de Jesus[1,2,3], G. Yang[1], A.A. Pimenta[3], A.J. de Abreu[3,4], G.A.S. Picanço[5], A.M. Santos[2,3], L.C.A. Resende[2,3], C.S. Carmo[1,2,3], L.F.R. Vital[1,2,3], I.S. Batista[3], J.R. Souza[3], K. Venkatesh[6], P.R. Fagundes[7], V.F. Andrioli[2,3], P.P. Batista[3], M.P.P. Martins[3], C. Wang[1], H. Li[1], Z. Liu[1], R.B. Kerr[8], L.V. Peres[9], R. da Silva[9]

[1]State Key Laboratory of Space Weather, National Space Science Center/Chinese Academy of Sciences, Beijing, China, [2]China-Brazil Joint Laboratory for Space Weather, National Space Science Center, São José dos Campos, Brazil, [3]National Institute for Space Research (INPE), São José dos Campos, Brazil, [4]Instituto Tecnológico de Aeronáutica (ITA), Divisão de Ciências Fundamentais, São José dos Campos, SP, Brazil, [5]Space Science Laboratory, University of Massachusetts Lowell, Lowell, MA, USA, [6]Physical Research Laboratory, Ahmedabad, India, [7]Universidade do Vale do Paraíba /IP & D, São José dos Campos, SP, Brazil, , [8]Computational Physics Inc., Lowell, MA, US, [9]Universidade Federal do Oeste do Pará (UFOPA), Santarém, Pará, Brazil.

Abstract

In this investigation, we present and discuss the response of the ionospheric F-layer in the Brazilian sector during a weak and intense geomagnetic storm in April 2025. The weak and intense storm investigated in this study show a minimum Dst of -33 nT on 15 April followed by -138 nT on 16 April. We present the variations of vertical total electron content (VTEC) and ionospheric F-layer parameters (h´F, hmF2, and foF2) obtained from Global Navigation Satellite System (GNSS) receivers and ionosondes, respectively, in the equatorial and low-latitude region. Also, Global-scale Observation of the Limb and Disk (GOLD), Fabry-Perot interferometer (FPI), and O/N2 ratio data are presented. During both storms, multiple prompt penetration electric fields (PPEFs) occurred. During the recovery phase of the intense storm, the pre‐reversal enhancement in the equatorial region was suppressed due to the westward PPEF, resulting in the suppression of the equatorial plasma bubbles (EPBs). The combined effect of equatorward thermospheric winds and the eastward PPEF caused abnormal upward movements in the ionosphere, resulting in positive ionospheric storms in both events. At low latitudes, negative ionospheric storms occurred due to changes in the O/N₂ ratio.

Speaker: Rodolfo de Jesus (Instituto Nacional de Pesquisas Espaciais)

4 identificação da superfície crítica de Alfvén e efeitos das componentes de conversão de energias

O Sol, estrela responsável pela principal fonte de energia do planeta Terra, impõe diversos processos físicos que afetam o clima espacial e se estendem para além da órbita terrestre. Devido à grande exposição e influência dos fenômenos advindos da estrela aos instrumentos espaciais, surge a necessidade de um entendimento mais robusto desse corpo celeste. Com esse intuito, foi realizado o lançamento da espaçonave Solar Parker Probe, que tem como um dos objetivos principais identificar os mecanismos de aquecimento da coroa solar e origens dos ventos solares através de dados coletados in situ. Nesse sentido, o presente trabalho se propõe identificar os efeitos das componentes de conversão de energias no plasma sub-alfvênico da superfície crítica de Alfvén, utilizando os dados da nave espacial. Para isso, serão avaliados os seguintes parâmetros de plasma: componentes do campo magnético, densidade de partículas, velocidade de partículas, velocidade da onda de Alfvén, beta do plasma, razão entre energia cinética e magnética e número de Mach alfvênico. Juntamente aos parâmetros do plasma também será avaliado, posteriormente, o balanço de energias (Em, Ek e Ei), a fim de remontar o contexto físico-espacial presenciado durante a trajetória da espaçonave e os efeitos impostos ao clima espacial.

Speaker: Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

5 Longitudinal Shock Extent and Characterization of Interplanetary Shocks Across Distinct Interplanetary Medium Environments Using Multi-Spacecraft Observations

Interplanetary shocks are fundamental agents of energy dissipation, particle
acceleration, and geomagnetic disturbance in the heliosphere, yet their complex
structure and geoeffective impacts are not fully understood. This study presents
a comprehensive investigation of interplanetary shock events using multi-spacecraft
observations from ACE, STEREO, Parker Solar Probe, and Solar Orbiter. Shocks
are identified through abrupt discontinuities in solar wind parameters, such as
magnetic field strength, plasma density, temperature, and velocity, with validation
performed using multi-spacecraft timing analysis to determine their propagation
direction and spatial extent. The Rankine-Hugoniot conservation relations are
systematically applied to compute key shock parameters, including shock normal
vectors, compression ratios, Alfvén Mach numbers, and the critical angle θBn,
enabling classification into quasi-parallel and quasi-perpendicular geometries.
Beyond shock characterization, the study examines associated interplanetary
structures, including Interplanetary Coronal Mass Ejection (ICMEs), sheath regions,
and magnetic clouds, to establish causal linkages between solar eruptions and shock
formation. Geoeffectiveness is assessed by correlating shock arrival times at near
Earth spacecraft with geomagnetic indices (Dst and Kp), quantifying how specific
shock characteristics influence magnetospheric disturbances. Statistical analysis
across varying longitudinal separations, building on prior work identifying a 50%
probability cut-off at 90◦ angular separation, provides insights into shock front
expansion and propagation evolution through the inner heliosphere. By integrating
multi-point observations, theoretical shock physics, and space weather impact
assessment, this research advances understanding of solar-terrestrial coupling and
enhances predictive capabilities for geomagnetic storm forecasting.
Keywords: Interplanetary Shocks. Multi-Spacecraft Observations. Rankine
Hugoniot Conditions. Geoeffectiveness. Interplanetary Coronal Mass Ejections.
Space Weather, Magnetic Clouds. Shock Parameters. Heliospheric Propagation.

Speaker: ALIU KARIM (NATIONAL INSTITUTE FOR SPACE RESEARCH (INPE))

6 Inversão DEM com SDO/AIA: quando um bom ajuste não garante a física

A distribuição de medida de emissão diferencial (DEM) descreve quanto plasma coronal existe em cada temperatura ao longo da linha de visada e é a base de mapas de medida de emissão (EM), temperatura média e largura térmica em regiões ativas. Com as seis bandas EUV do SDO/AIA (94, 131, 171, 193, 211 e 335 Å), obter a DEM é um problema inverso mal posto, cujo resultado depende da resposta em temperatura K(T) de cada canal e do modelo de erro. Apresentamos um pipeline genérico e reprodutível para a inversão DEM pixel a pixel, com pré-processamento pelo aiapy (apontamento, registro e correção de degradação com normalização pelo SDO/EVE), incertezas por pixel calculadas com o estimador oficial da equipe do AIA, inversão regularizada de Hannah & Kontar (2012) via demregpy, momentos da DEM (EM, ⟨log T⟩, T_em e σ_logT) com incertezas propagadas, máscara de qualidade 𝜒2 reduzido ≤ 3 e reprojeção para a grade CEA do SHARP, para comparação com o campo magnético fotosférico. Aplicamos o pipeline às regiões ativas NOAA 13663 (02/05/2024, ~12 h antes de um flare classe X) e NOAA 12712 (29/05/2018) e mostramos que a consistência entre a calibração dos dados e a K(T) determina o resultado físico mais do que os indicadores de ajuste. Combinar uma K(T) normalizada pelo EVE com dados sem essa normalização produziu um ajuste aparentemente aceitável, com 𝜒2 mediano de 1,29 e 64% dos pixels válidos, mas com EM ~23% menor e ⟨log T⟩ ~0,09 dex menor que a solução consistente, um artefato da mistura de calibrações. Já a correção empírica /chiantifix do canal de 94 Å, usada em trabalhos de referência (Hannah & Kontar 2013; Cheung et al. 2015), foi derivada para respostas baseadas no CHIANTI 7. Com a resposta atual (V10, CHIANTI 9.3), ela superestima o 94 Å em 10% na AR 13663 e em 36% na AR 12712, eleva o 𝜒2 mediano de 1,33 para 2,35 e de 1,78 para 5,02 e reduz os pixels válidos de 65% para 55% e de 60% para 38%. Na AR 12712, cria ainda um déficit no pico do Fe XVIII e uma componente quente espúria em log 𝑇 ≈ 7,1, em acordo com o alerta de Del Zanna et al. (2015). Mostramos também que a fração de pixels aceitos depende do limiar de 𝜒2 e do SNR, de modo que aceitar mais pixels não significa obter uma física mais correta. Com a configuração adotada (resposta V10 normalizada pelo EVE, sem chiantifix), a AR 13663 apresenta 𝜒2 mediano de 1,33, 65% de pixels válidos, T_em mediana de 2,84 MK e σ_logT de 0,33 dex, com incertezas estatísticas de ~4,5% em EM e 0,02 dex em ⟨log T⟩. O canal de 335 Å, porém, segue subestimado em 27–34% em todas as configurações e nas duas regiões, uma questão ainda em aberto. Concluímos que 𝜒2 e cobertura são necessários, mas não suficientes: antes de interpretar mapas de
temperatura e EM, é preciso verificar a consistência entre calibração, dados atômicos e modelo de erro.

Speaker: Bruno Fernandes Garcia

12:00 Lunch | Almoço

Invited Talk | Palestra Convidada: EMBRACE

Conveners: Bruno Fernandes Garcia, Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

7 Estudo e Monitoramento Brasileiro do Clima Espacial - EMBRACE

Speaker: Joaquim Costa (INPE - National Institute for Space Research)

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

Conveners: Bruno Fernandes Garcia, Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

8 First steps of the study of the long-term effects on the diurnal variation of the geomagnetic field in the SAMA region

Secular variations in the geomagnetic field gradually alter the magnetic configuration that controls the ionospheric current systems responsible for the diurnal variation. However, this coupling has not yet been systematically quantified in the South American Magnetic Anomaly (SAMA) region. Therefore, the objective of this study is to investigate the long-term effects on the diurnal variation of the geomagnetic field by analyzing the coupling between the main field and ionospheric current systems. The methodology consists of a comparative analysis of magnetic stations in the SAMA region, using data from the Estudo e Monitoramento Brasileiro do Clima Espacial Magnetometer Network (EMBRACE MagNet) and the International Real-time Magnetic Observatory Network (INTERMAGNET). Spectral analysis and correlation techniques are applied to quantify the connection between secular and diurnal geomagnetic variations in the SAMA region. The expected results include quantifying the effect of long-term variation on the amplitude and phase of diurnal variation, identifying the characteristic time scales of coupling, and predictive empirical models applicable to space weather studies. This research will contribute to a fundamental understanding of regional geomagnetic-ionospheric coupling and improving diurnal variation models, with potential applications in geomagnetic monitoring and space weather forecasting.

Speaker: Guillermo Caro (Instituto Nacional de Pesquisas Espaciais)

9 ESTIMATIVA E REPRESENTAÇÃO DO CAMPO GEOELÉTRICO INDUZIDO POR TEMPESTADES MAGNÉTICAS

Tempestades magnéticas são perturbações do campo magnético terrestre causadas pela interação do vento solar com a magnetosfera. As rápidas variações geomagnéticas associadas a esses eventos induzem campos elétricos na superfície terrestre, podendo gerar Correntes Geomagneticamente Induzidas (GICs) que afetam redes elétricas e sistemas de comunicação. Embora mais intensas em altas latitudes, as GICs também ocorrem na América do Sul, onde sua magnitude depende tanto das variações do campo magnético quanto da estrutura regional de condutividade elétrica em subsuperfície. Nesse contexto, foi desenvolvido um dashboard em Python/Streamlit para estimativa do campo geoelétrico, integrando dados geomagnéticos da rede Embrace-Magnet e tensores de impedância magnetotelúrica. Os dados magnéticos são adquiridos do servidor Embrace, convertidos para unidades físicas e componentes cartesianas, submetidos à remoção de outliers, preenchimento de lacunas e remoção de tendência. As componentes horizontais Bx e By são transformadas para o domínio da frequência via Transformada Rápida de Fourier, enquanto os elementos do tensor de impedância Zxx, Zxy, Zyx, Zyy são reconstruídos a partir das partes real e imaginária e interpolados por splines cúbicas em escala logarítmica. Os campos geoelétricos Ex e Ey são obtidos pela multiplicação do tensor de impedância pelos espectros magnéticos e posteriormente convertidos ao domínio temporal pela Transformada Inversa de Fourier. A aplicação foi avaliada durante a tempestade geomagnética extrema G5 de 10–12 de maio de 2024, utilizando as estações magnéticas de São Luís (SLZ; 2,59417° S, 44,20972° O) e São José dos Campos (SJC; 23,20862° S, 45,96353° O), associadas às estações magnetotelúricas BAC (4,24000° S, 44,80000° O) e APG33 (23,68400° S, 51,72200° O), respectivamente. Os resultados indicaram predominância da componente Ey, com amplitudes próximas a -50 mV/km no nordeste e -80 mV/km no sudeste do Brasil. Essas diferenças refletem a influência conjunta da intensidade da tempestade, de fenômenos regionais como o Eletrojato Equatorial e a Anomalia Magnética do Atlântico Sul, além dos contrastes locais de condutividade. O modelo desenvolvido integra dados geomagnéticos e magnetotelúricos, tornando o dashboard uma ferramenta para análise regional de campos geoelétricos e avaliação da suscetibilidade às GICs.

Palavras-chave: Tempestades Geomagnéticas. Campo Geoelétrico. Método Magnetotelúrico. Correntes Geomagneticamente Induzidas.

Speaker: Jorge Camasmie (Universidade de São Paulo)

10 Latitudinal dependence of the cosmic noise absorption across the SAMA based on recent measurements

The South American Magnetic Anomaly (SAMA) evolves in terms of the location of Earth’s magnetic field's weakest point, its span, and its intensity while remaining the region of weakest magnetic-field intensity. This makes the region particularly suitable for examining the coupling between magnetospheric forcing and the lower ionosphere. Previous observations show that cosmic noise absorption (CNA) varies systematically with latitude across the SAMA. This makes the region particularly suitable for examining the coupling between magnetospheric forcing and the lower ionosphere. For example, previous observations show that cosmic noise absorption (CNA) varies systematically with latitude across the SAMA. Nevertheless, it remains unresolved whether the differences observed between stations arise from the regional magnetic-field configuration itself or from the common storm-time forcing experienced during individual disturbances. Earlier studies established the existence of this spatial variation, but they did not quantitatively isolate the contribution of the local geomagnetic field from that of external forcing using contemporary multi-station observations. The upcoming availability of new observations from an expanded riometer network may make it possible to test this question across multiple disturbances rather than infer it from isolated case studies. To advance our understanding, we will use simultaneous riometer observations from stations located across and beyond the SAMA, and analyze a selected set of geomagnetic disturbances and solar events. For each event, CNA onset, maximum amplitude, duration, and integrated absorption will be quantified and related to geographic and geomagnetic latitude, magnetic-field intensity and configuration, and external solar-wind and geomagnetic drivers. Event-by-event and multi-station analyses will then be used to assess whether the observed latitudinal relationships persist across disturbances and stations or instead reflect event-specific particle precipitation patterns. Supporting information may come from ionosonde observations to provide a complementary test of whether enhanced CNA is accompanied by partial or complete ionogram blackout.

Speaker: Solomon Atotuomah (INPE)

11 Electron Flux Variations Associated with Plasmaspheric Plumes and Hiss Waves under Different Solar Wind Conditions

The variation of electron flux in the energy range from 0.015 to 51.768 keV is analyzed in association with the occurrence of plasmaspheric plumes under different solar wind conditions. During the formation of these structures, regions of enhanced plasma density extend to higher L-shell values, allowing the propagation of whistler-plume waves. The observed flux variations may be associated with wave–particle interaction processes occurring in these regions, suggesting interaction between hiss waves and the low-energy electron population of the plasmasphere. In this work, two distinct periods are analyzed: a geomagnetically quiet interval on 2015-08-04/05 and a disturbed interval during the arrival of an ICME on 2015-03-01. During the quiet period, in the presence of a plasmaspheric plume and whistler-plume waves, a decrease in electron flux is observed in the energy range from 0.043 to 0.140 keV, followed by a rapid enhancement after the plume passage. In the higher-energy channels, between 27.153 and 41.749 keV, an increase in electron flux is observed during the plume occurrence; however, this enhancement does not begin at the exact onset of the plume and decreases before the plume ends, with flux levels increasing again after the plume passage. During the disturbed interval associated with the ICME, electrons in the energy range from 0.526 to 1.047 keV exhibit an enhancement during the occurrence of the plume and the presence of whistler-plume waves, reaching a maximum peak followed by a gradual decrease. In contrast, lower-energy electrons around 0.067 keV and higher-energy electrons above 4.147 keV remain relatively stable throughout the event. These results indicate that plasmaspheric plumes associated with whistler-plume waves may contribute to distinct electron flux responses under different solar wind conditions, particularly within low-energy electron populations in the plasmasphere.

Speaker: Pedro Henrique Ferreira Fister

15:30 Coffe Break

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

Conveners: Bruno Fernandes Garcia, Caroline Botelho (Instituto Nacional de Pesquisas Espaciais)

12 Understanding the Mechanisms Driving Particle Precipitation over the South Atlantic Magnetic Anomaly during the June 2015 Geomagnetic Storm

Energetic particle precipitation is common in the South Atlantic Magnetic Anomaly (SAMA), where the weakened geomagnetic field allows particles from the inner radiation belt to reach the atmosphere. During geomagnetic disturbances, this precipitation can be enhanced and may produce ionospheric signatures typically observed in auroral regions. However, the mechanisms controlling the storm-time enhancement and spatial extent of precipitation over the SAMA remain poorly understood. This study investigates the storm-time dynamics of energetic electrons and their precipitation over the SAMA during a geomagnetic storm on 22 June 2015 following interplanetary coronal mass ejections (ICMEs). We combine energetic particle and plasma wave observations from the Van Allen Probes with particle flux measurements from PROBA-V/EPT over the Brazilian sector. Ionosonde observations investigate the response of the lower ionosphere to enhanced particle precipitation. The analysis focuses on electrons with energies of 10s of keV to 800 keV. During the storm, particles were transported inward from the outer magnetosphere, filling the slot region and populating lower-L-shells. Concurrently, the plasmapause was compressed and enhanced hiss-wave activity was observed in the plasmasphere. The enhanced particle fluxes in the inner radiation belt were accompanied by an increase in fluxes over the SAMA and an expansion of the precipitation region beyond the nominal SAMA footprint, extending toward both lower latitudes and auroral-ward latitudes. Ionosonde observations from Cachoeira Paulista revealed the formation of an intense auroral-like sporadic-E layer in the E region during the storm recovery phase on June 24, providing an independent indication of enhanced energetic particle input into the atmosphere. These observations suggest that enhanced precipitation over the SAMA and the delayed response of ionosphere may be associated with the storm-time inward transport and subsequent scattering of energetic electrons into the atmosphere. We use simulations from the Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model to reconstruct storm-time evolution of the inner radiation belt and quantify the relative roles of radial transport and pitch-angle scattering in producing the enhanced precipitation.

Speaker: Karen Julia Coldebella Ferreira (National Institute for Space Research (INPE) / NASA Goddard Space Flight Center)

13 A magnetosfera de Júpiter e sua interação com os satélites Galileanos

O intenso campo magnético de Júpiter, aliado à sua rápida rotação, impõe ao ambiente ao redor do planeta um regime de corrotação de plasma que se estende de modo a alcançar os satélites Galileanos com velocidades relativas sub-Alfvénicas. Nessa configuração, cada satélite responde de forma distinta à passagem do plasma magnetosférico de Júpiter, e é justamente dessa resposta que se originam parte das emissões aurorais observadas em altas latitudes jovianas, incluindo emissões de rádio decamétricas (DAM). Esse trabalho concentra-se na revisão teórica da interação eletrodinâmica entre Júpiter e os satélites Galileanos e evidências observacionais de rádio associadas a esse acoplamento: desde o reconhecimento pioneiro do controle exercido por Io sobre as emissões decamétricas jovianas, comprovado estatisticamente em catálogos como os do Nançay Decameter Array, até a identificação mais recente e ainda pouco frequente de assinaturas induzidas por Europa e por Ganímedes. Por fim, discute-se o papel das missões JUICE e Europa Clipper, cuja chegada ao sistema joviano a partir de 2030 deve fornecer os primeiros dados in situ capazes de testar diretamente essas previsões para Europa, Ganímedes e Calisto.

Speaker: Emilly Rosa

Tuesday 6 October

Invited Talk | Palestra Convidada

Conveners: Suallyson Araújo (INPE), Guillermo Caro Lillo (Instituto Nacional de Pesquisas Espaciais)

14 Detection of the Atypical Sporadic E Layer Due to Anomalous Extra Ionization During Magnetic Storms over Brazilian Regions

Speaker: Laysa Resende (INPE)

Oral Presentations | Apresetações Orais: Apresentações alunos

Apresentação dos Alunos

Conveners: Suallyson Araújo (INPE), Guillermo Caro Lillo (Instituto Nacional de Pesquisas Espaciais)

15 CLIMATOLOGY OF GNSS-DERIVED IONOSPHERIC DISTURBANCE INDICES OVER THE SAMA REGION

Ionospheric disturbance indices have been developed to quantify ionospheric variability and identify perturbations associated with space weather phenomena, given that the ionosphere is a highly dynamic region of the Earth's upper atmosphere that is strongly influenced by solar and geomagnetic activity. Variations in ionospheric electron density can significantly affect radio wave propagation and satellite-based navigation systems.
This study proposes a climatological analysis of ionospheric disturbance indices derived from data collected by Global Navigation Satellite System (GNSS) receivers using the Open Advanced System for Ionospheric Studies (OASIS) platform (Picanço et al., 2025). In particular, the Total Electron Content (TEC) variation (ΔTEC), the Rate of TEC Index (ROTI), and the Sudden Ionospheric Disturbance Index (SIDX) are analyzed to investigate their behavior and sensitivity under different solar and geomagnetic conditions to support the development of a disturbance scale.
The analysis focuses on ionospheric variability over regions influenced by the South American Magnetic Anomaly (SAMA), where enhanced particle precipitation can significantly affect the ionospheric environment and impact satellite-based communication and navigation signals. Investigating the climatological behavior of these indices in this region can provide important insights into ionospheric variability under the influence of the SAMA. Therefore, the purpose of this study is to advance the use of ionospheric disturbance indices for monitoring variability in the ionosphere and improving the understanding of its behavior under different space weather conditions.

Speaker: Anita Jungton Valcorte

16 Equatorial Ionospheric Electrodynamics at Sunset: From the Pre-Reversal Enhancement to Plasma Irregularities

The equatorial ionosphere undergoes a profound electrodynamic reconfiguration during the sunset period. The rapid decay of E-region conductivity modifies the electrodynamic coupling and current closure between the E and F regions. In combination with the F-region dynamo driven by thermospheric winds, this process gives rise to the Pre-Reversal Enhancement of the zonal electric field (PRE). The resulting increase in the upward E × B plasma drift lifts the F region to higher altitudes, creating favorable conditions for the development of the generalized Rayleigh–Taylor instability and the subsequent generation of equatorial plasma irregularities. The occurrence and intensity of these processes are strongly modulated by atmospheric wave coupling, solar activity, and geomagnetic disturbances. This work discusses the physical mechanisms governing the sunset electrodynamics of the equatorial ionosphere, with emphasis on the electrodynamic coupling between the E and F regions and its role in controlling plasma transport and instability development. Observational examples from ionosonde measurements will be presented to illustrate how key ionospheric parameters, including hmF2, foF2, vertical plasma drift, and spread-F signatures, can be used to investigate the evolution of equatorial ionospheric electrodynamics and the onset of plasma irregularities.

Speaker: ÂNGELA VALENTIM (INPE)

17 SPORADIC E LAYERS EXHIBITING SPREAD ECHOES IN THE SOUTH AMERICAN MAGNETIC ANOMALY: MORPHOLOGY AND DYNAMICS

Sporadic E (Es) layers are electron density structures typically found between 90 and 130 km altitude. They are composed predominantly of metallic ions and commonly form through wind shear at these heights. This study investigates the dynamical and morphological properties of Es layers exhibiting spread echoes over Santa Maria (RS), a station located within the South American Magnetic Anomaly (SAMA) region. We examine how the vertical extent of spread-Es traces evolves at fixed frequencies, as well as event duration and local time dependence. The analysis uses manually scaled ionograms recorded by the digital ionosonde at Santa Maria during selected spread-Es events.

Speaker: Jaziel Campelo (Instituto Nacional de Pesquisas Espaciais)

18 Studies of Maximum Usable Frequency (MUF) in Brazilian Ionospheric Stations and Its Prediction Based on Machine Learning

The Brazilian ionospheric sector is particularly complex due to the influence of the Equatorial Ionization Anomaly (EIA) and the South American Magnetic Anomaly (SAMA). Also, the large declination angle of the magnetic field and phenomena like disturbed electric fields and plasma irregularities can produce significant spatial and temporal variations in radio communications. Thus, the Maximum Usable Frequency (MUF) may be a key parameter for high-frequency (HF) radio-wave propagation studies, since it represents the highest frequency that can support reliable HF communication over a specified path. Accurate MUF prediction is essential for frequency management, communication planning, aviation, maritime operations, and other HF-dependent systems. Thus, this research aims to characterize MUF variability over Brazil and develop a machine-learning-based framework for short-term prediction under quiet and disturbed ionospheric conditions. Initially, ionosonde observations from Cachoeira Paulista and Boa Vista will be used to investigate regional MUF behavior. The analysis will subsequently be expanded to other Brazilian stations to identify the main physical and geophysical drivers of MUF variability and quantify its response to geomagnetic disturbances. The expected outcome is a validated and regionally adapted prediction framework that contributes to improved HF propagation assessment, space-weather monitoring, and operational ionospheric forecasting over Brazil.

Speaker: Oluwasola Akinbode (INPE)

10:30 Coffee Break

Invited Talk | Palestra Convidada

Conveners: Suallyson Araújo (INPE), Guillermo Caro Lillo (Instituto Nacional de Pesquisas Espaciais)

19 TBD

Speaker: Kleber Pinheiro Naccarato (INPE)

Oral Presentations | Apresetações Orais: Apresentação Alunos

Apresentação dos Alunos

Conveners: Suallyson Araújo (INPE), Guillermo Caro Lillo (Instituto Nacional de Pesquisas Espaciais)

20 Study Of The Propagation Of Positive Upward Leaders Using High-Speed Cameras

In the context of lightning physics, upward lightning represents a rare and distinct class of electrical discharges that originate from ground-based elevated structures and propagate toward storm clouds. In this study, a Phantom v310 high-speed camera located in Johannesburg, South Africa, served as the primary instrumentation to capture the detailed development of upward positive leaders. Analysis of 54 video recordings, encompassing 71 distinct lightning cases, revealed that the majority exhibited recoil leaders (76%) and branching (89%), frequently co-occurring (75%), with recoil leaders retracing decaying branch channels in several instances. Average speeds were on the order of $10^4\text{ m/s}$, predominantly concentrated below $5.0 \times 10^4\text{ m/s}$ and largely associated with branching events, whereas the two cases with the highest propagation speeds exhibited no branching. Along their upward trajectory, leaders propagated primarily vertically during initiation, showing a decrease in the vertical velocity component and an increase in the horizontal component as they approached the cloud base in stratiform storm regions. Regarding the correlation between channel luminosity and leader speed, a wide dispersion of correlation coefficients was observed. Nevertheless, 51% of the cases demonstrated a moderate to very strong positive correlation, partially supporting the proposed hypothesis. The complexity of lightning events, influenced by multiple physical and atmospheric parameters, contributes to the observed dispersion in the analyzed characteristics. Future research should incorporate additional parameters and investigate storm cloud structures to deepen the understanding of the phenomenology associated with upward positive leaders.

Speaker: João Carlos Martins Alves (Instituto Nacional de Pesquisas Espaciais)

21 Previsão imediata de tempo (nowcasting), tempo severo e raios

Neste trabalho, será abordada a previsão imediata de tempo (nowcasting), o significado de tempo severo e a coleta de relatos de tempo severo no Brasil. Também será abordado como os dados de descargas atmosféricas (especificamente, os raios) podem ser utilizados na previsão imediata e na caracterização de ocorrência de tempo severo. Ainda, será abordado um panorama do estudo de raios utilizando câmeras de alta velocidade.

Speaker: Diego Rhamon

22 ANÁLISE DE DESCARGAS ATMOSFÉRICAS POR VISÃO COMPUTACIONAL EM CÂMERAS DE ALTA VELOCIDADE

Este trabalho apresenta um pipeline não supervisionado para análise das características de propagação de descargas nuvem-solo positivas (+CG) e negativas (-CG), registradas por câmeras de alta velocidade. A partir de 25 vídeos (8 positivos e 17 negativos, exportados em TIFF de 16 bits), o modelo EfficientNet-B3 foi utilizado como extrator genérico de características visuais, sem ajuste fino para o domínio de raios. Cada sequência foi representada por um vetor de agregação temporal de 1536 dimensões, combinando média, desvio-padrão e taxa de variação das features ao longo do tempo. Após redução de dimensionalidade via PCA e UMAP, o algoritmo K-Means foi aplicado para agrupamento, avaliado pelos índices de Silhueta e Rand Ajustado (ARI). Para k=2, o método atingiu Silhueta de 0,645 e ARI de 0,691 em relação aos rótulos de polaridade atribuídos manualmente, sem que qualquer informação de polaridade fosse fornecida durante o agrupamento. A análise dos perfis temporais de intensidade visual e de taxa de variação entre quadros revelou padrões fisicamente interpretáveis e consistentes com a morfologia conhecida de líderes positivos (canal único, poucas ramificações) e negativos (propagação escalonada, altamente ramificada). Os resultados demonstram que representações visuais genéricas, extraídas sem treinamento específico no domínio, são suficientes para discriminar a polaridade de descargas atmosféricas de forma não supervisionada, abrindo caminho para extensões futuras com redes treinadas especificamente para capturar características morfológicas como densidade de ramificação e geometria do canal.

Speaker: Hentony Barboza (INPE)

12:00 Lunch

Invited Talk | Palestra Convidada

Conveners: Guillermo Caro Lillo (Instituto Nacional de Pesquisas Espaciais), Suallyson Araújo (INPE)

23 Marcos de uma trajetória acadêmica na Física Solar -Terrestre

Speaker: Dr Arian González (UNIVAP)

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

Conveners: Guillermo Caro Lillo (Instituto Nacional de Pesquisas Espaciais), Suallyson Araújo (INPE)

24 Exploring Jupiter’s Aurora

All magnetized planets in the Solar System exhibit auroral emissions at different wavelengths. Planetary auroral activity provides a remote projection of processes occurring within the planetary magnetospheres. Jupiter possesses the most powerful and complex aurora in the Solar System, with emissions organized into three distinct regions around its magnetic poles: the main auroral oval, the polar emissions, and the magnetic footprints of Jovian satellites.
This work aims to revisit the works of Clarke et al. (2004) and Clarke (2012) and provide an introductory overview of Jupiter’s aurora and the magnetospheric processes associated with its different auroral emissions.

Speaker: Hadassa Raquel Peixoto Jácome (INPE)

25 Development of 'Heliogap': A Python Library for Solar Wind and Ground-Based Magnetometers Data Curation and Gap Analysis

The ongoing study aims to predict geomagnetic disturbances at low latitudes with machine learning. For this, however, a treatment of missing data (gaps) in satellites and ground stations is necessary. In order to solve this problem, the Python library heliogap was developed, which automates the extraction, cleaning, and statistical gap analysis of solar wind parameters from OMNIweb/ACE and ground magnetic field data from the Embrace MagNet network.The library features a self-healing cache architecture and a mathematical engine optimized for the processing of millions of data points, being capable of isolating continuous blocks of data. It evaluates multiple interpolation methods, such as Akima, nearest, and quadratic, in simulated data gaps, generating standardized error matrices (RMSE, MAE, WMAPE).Preliminary results provided a statistical diagnosis of the gap distributions. By establishing a fully automated data curation pipeline, heliogap creates the base for the future training of predictive AI algorithms and for the subsequent deployment of a real-time monitoring platform.

Speaker: José Neto (INPE)

26 Wavelet Coherence and Cross Wavelet Analysis of F10.7cm index and H-component at Jataí (lat. 17° 52’, long. 51° 43’ ), Brazil, in 2022 year

In this work we analyse the H-component of geomagnetic field at low latitude region (-17.88° S), the F10.7cm solar flux index, the Interplanetary Magnetic Field (IMF), the y-component of Solar Wind Electric Field (Ey) and the solar wind speed (Vsw) using multiscale analysis methods. The objective is to study coherence and phase relationship between these indexes, during geomagnetic storm periods in the ascending phase of solar cycle 25. The H-component data used was provided by INPE's EMBRACE magnetometer located at Jataí, Goiás state, Brazil. The solar radio flux index, IMF, and Ey Solar Wind Electric Field were obtained from SPDF NASA/GSFC OMNIWeb interface. By applying of wavelet transform and its derivatives, Cross Wavelet transform (XWT) and Wavelet Coherence Transform (WCT), correlations between H and F10.7 cm were computed in certain scales and periods of the year corresponding to moderate geomagnetic storms, which can be confirmed by Disturbance Storm Time (DST) index analysis. Furthermore, phase relationship between data was obtained according to Torrence and Webster, 1999. We observed that the H-component is lagging F10.7 cm, as expected in theory, with the exception of two months: March and August. To elucidate this issue, the same methods were applied to Solar wind Data, namely IMF, Ey and Vsw.

Speaker: Érik A. Barbosa (National Institute for Space Research (INPE))

27 VISUALIZAÇÃO E PROCESSAMENTO DE DADOS SOLARES PARA O ESTUDO DE CASO COMPARATIVO DAS REGIÕES ATIVAS NOAA AR 12712 E NOAA AR 3664

O campo magnético das regiões ativas é a principal fonte de energia das explosões solares (flares) e das ejeções de massa coronal (CMEs), fenômenos que governam o clima espacial na vizinhança terrestre. Regiões de configuração magnética simples raramente produzem eventos intensos, enquanto regiões complexas podem gerar sequências de flares de classe M e X. O presente trabalho investiga quais parâmetros fotosféricos distinguem esses dois comportamentos e como eles evoluem ao longo da passagem das regiões pelo disco solar. Foram comparadas a NOAA AR 12712 (maio de 2018), de classificação magnética , e a NOAA AR 13664 (maio de 2024), de classe βγδ, responsável por 12 flares de classe X e associada à tempestade geomagnética de maio de 2024 (Gannon Storm). Utilizaram-se magnetogramas vetoriais e parâmetros do produto SHARP (hmi.sharp_cea_720s), obtidos pelo instrumento Helioseismic and Magnetic Imager (HMI) a bordo do Solar Dynamics Observatory (SDO). Os dados foram processados com rotinas em Python baseadas nas bibliotecas SunPy, Astropy, NumPy e Matplotlib. As séries temporais foram restritas a longitudes de até 60° do meridiano central, para reduzir efeitos de projeção, e confrontadas com o catálogo de flares do GOES. Os parâmetros foram analisados em dois grupos. O primeiro reúne os extensivos, que dependem do tamanho da região: fluxo magnético total, helicidade de corrente total e densidade de energia livre fotosférica. O segundo reúne os intensivos, que caracterizam a complexidade do campo: ângulo de cisalhamento médio, inclinação média e torção média. Analisou-se também o parâmetro R, associado ao fluxo próximo à linha de inversão de polaridade. Espera-se determinar se as diferenças entre as regiões decorrem principalmente do tamanho ou da complexidade do campo, e quais parâmetros apresentam variações associadas aos flares principais da AR 13664. Os resultados preliminares dessa comparação serão apresentados no evento e o conjunto de dados processado será organizado em arrays para servir de condição de contorno a modelos de extrapolação do campo magnético baseados em redes neurais informadas pela física (PINNs), desenvolvidos pelo grupo de Heliofísica e Solar AI do INPE no contexto do projeto GSST.

Speaker: Manuela Antonelli (IFSP)

15:30 Coffee Break

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

28 Characteristics of EUV emission during a X8.2 flare observed in the solar limb

Solar flares are characterized by rapid enhancements in electromagnetic emission across multiple wavelengths. This study investigates the extreme ultraviolet (EUV) emission associated with the X8.2-class solar flare that occurred near the solar limb on 10 September 2017 in active region NOAA 12673. The region exhibited a 𝛽𝛾 magnetic configuration with interacting opposite-polarity flux systems and multiple polarity inversion lines. EUV observations obtained between 13:00 and 19:00 UT indicate that the plasma was initially confined within a complex magnetic topology connecting distinct photospheric regions. Prior to flare onset, the coronal structure evolved quasi-statically, followed by a dynamic magnetic reconfiguration that produced a post-flare loop arcade. A precursor plasma jet was detected before the eruption, and observations in the 94 Å and 131 Å channels revealed a filamentary structure consistent with a possible current sheet. Light-curve analysis shows an initial emission enhancement at approximately 15:45 UT associated with the jet, followed by a rapid increase culminating in a primary peak near 16:07 UT. Wavelet analysis identified short-period oscillations superimposed on the EUV emission from jet initiation through the onset of the decay phase. The mean vertical emission profile indicates upward propagation of the dominant emission source to heights of approximately 42 Mm, accompanied by a progressive decrease in propagation velocity. Statistical analysis revealed a transition from approximately Gaussian pre-flare intensity distributions to increasingly right-skewed distributions during the eruption, with corresponding increases in variability, skewness,and kurtosis.

Speaker: Jean Santos (instituto nacional de pesquisas espaciais)

29 Review of the main EFfects SignAlIng the ElectRodynamic CouplIng between the AtmospherE and Space (FAIRIES)

The Transient Luminous Events (TLEs) are hybrid atmosphere-space plasmas that directly couple the Troposphere with the Ionosphere. They are transient and weakly ionized, with low-light level optical emissions (~kR- few MR), therefore observable only at night. They are excited in the upper atmosphere above thunderstorms by lightning discharges electromagnetic fields. These short plasmas (µs – few 100’s ms) span the whole region from ~20-110 km, piercing the bottom of the nighttime Ionosphere. The main TLE types currently known are sprites, halos, blue jets, gigantic jets and elves. High Energy Emissions from Thunderstorms (HEETs), whose hard radiation species measured up to date are X-Rays, ϒ-Rays, electrons, positrons and neutrons, may couple the Troposphere directly with the Magnetosphere. HEET were initially believed to be generated by sprites, however, current theories suggest, for example, that Terrestrial Gamma-Ray Flashes (TGFs), discovered using NASA’s astrophysical satellite Compton Gamma-Ray Observatory, initiate inside the thunderstorm at ~11-15 km altitude, in association with lightning. Their energies (~20 keV-100 MeV) are comparable to astrophysical Gamma Ray Bursts (GRBs), e.g. emitted when a star goes supernova. These two classes of phenomena compose the EFfects SignAlIng the ElectRodynamic CouplIng between the AtmospherE and Space (FAIRIES). This talk will review the currently known FAIRIES.

Speaker: Eliah São Sabbas (INPE)

Wednesday 7 October

Invited Talk | Palestra Convidada

Conveners: Jaziel Campelo (Instituto Nacional de Pesquisas Espaciais), Karen Julia Coldebella Ferreira (National Institute for Space Research (INPE) / NASA Goddard Space Flight Center)

30 Geofísica Espacial em Todo Lugar: Conexões entre Ciência, Tecnologia e outras coisas mais

Speaker: CLAUDIA MEDEIROS (INPE)

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

Conveners: Jaziel Campelo (Instituto Nacional de Pesquisas Espaciais), Karen Julia Coldebella Ferreira (National Institute for Space Research (INPE) / NASA Goddard Space Flight Center)

31 The INPE–NSSC Na-K LIDAR Program: A Review of Scientific Achievements and Future Perspectives

Over the past decade, the collaboration between the National Institute for Space Research (INPE, Brazil) and the National Space Science Center (NSSC, Chinese Academy of Sciences) has significantly advanced the study of the Mesosphere and Lower Thermosphere (MLT) through the operation of the dual-beam sodium and potassium (Na-K) resonance LIDAR at São José dos Campos, Brazil. As the only dual-metal resonance LIDAR currently operating in South America, this unique facility has enabled high-resolution observations of mesospheric Na and K layers, providing new insights into the dynamics, chemistry, and ionized and neutral atmospheric coupling processes in the low-latitude MLT region. This presentation reviews the main scientific achievements of this long-term collaboration, including studies of morphology of these metallic layers, Sporadic Na and K layers, C-structures, mesospheric instabilities, meteoric metal deposition, stratospheric aerosols, and the influence of the South Atlantic Magnetic Anomaly (SAMA) and geomagnetic storms on mesospheric metal layers. The integration of LIDAR observations with meteor radar, ionosonde, all-sky imager, satellite measurements, and numerical modeling has substantially improved our understanding of upper-atmosphere processes over South America. Finally, we discuss future perspectives of the collaboration, including diurnal measurements as well as the application of artificial intelligence for automated meteor trail detection and the investigation of the role of the SAMA in meteor trail evolution and meteoric metal chemistry. These developments represent a natural continuation of ten years of successful scientific cooperation and technological innovation between INPE and NSSC.

Speaker: Vania Fátima Andrioli (INPE)

32 Observations of the Midnight Brightness Wave Across Brazil: Latitudinal Evolution and Propagation Speed

The Midnight Brightness Wave (MBW) is characterized by an enhancement in the intensity of terrestrial airglow emission near local midnight, particularly in the OI 630.0 nm emission, and is associated with the Midnight Temperature Maximum (MTM), which occurs mainly in equatorial and low-latitude regions. Brazil's continental extent and its broad latitudinal and longitudinal coverage provide a favorable configuration for observing this phenomenon at different locations and investigating its spatial evolution. In this study, all-sky imaging data were analyzed from four sites distributed over the Brazilian territory: São João do Cariri, PB (7.4°S; 36.5°W), Bom Jesus da Lapa, BA (13.3°S; 43.4°W), Cachoeira Paulista, SP (22.0°S; 45.0°W), and São Martinho da Serra, RS (29.5°S; 53.9°W). These observations provide an opportunity to investigate the occurrence and spatial extent of the MBW over a broad latitudinal range, from equatorial and low-latitude regions toward mid-latitudes. This work aims to characterize the MBW events observed at these sites, investigate their spatial and temporal development, including propagation speed and longitudinal variability. The combined analysis of observations from multiple sites contributes to a better understanding of the spatial distribution and propagation of the MBW.

Speaker: Suallyson Araújo (INPE)

33 Um código simples das ondas gravidade acústicas

Recentes estudos mostram que o monitoramento dos climas extremos no Near-Real-Time facilita o Now-Casting dos climas com feedback da simulação do mecanismo de acoplamento desses climas com a atmosfera e a ionosfera. O mecanismo envolve as ondas de gravidade acústicas (AGWs) e sua simulação no Near-Real-Time. Neste aspecto, a simulação rápida pode melhorar o desempenho do nowcasting. Este trabalho apresenta um código simples das ondas de gravidade acústicas que produz os efeitos dos climas extremos na atmosfera-ionosfera antes da sua detecção.

Speaker: Esfhan alam kherani (Researcher, INPE)

34 Simultaneous sodium and potassium lidar observations of meteor trails in the mesosphere and lower thermosphere (2018–2023)

Meteoric ablation is the main source of the metal layers in the mesosphere and lower thermosphere (MLT). Simultaneous observations of different metals in individual meteor trails can reveal how meteoroids ablate and how the trails evolve. We present a statistical study of 385 meteor trail events detected simultaneously by Na and K resonance lidars at sao jose dos campos on 174 nights between February 2018 and June 2023. For each event we derived the peak altitude, peak density, and column abundance of both metals. The trails occurred between 80 and 97 km (median 87.1 km). The Na and K signatures were co-located, confirming a common meteoric origin. Most events lasted less than one minute, but one trail on 10 March 2020 persisted for 37 minutes at 83 km. Na and K column abundances were strongly correlated (Spearman ρ = 0.75). The Na/K column ratio had a median of 8.4 (interquartile range 5.7–12.6) and was independent of altitude. This ratio is below the chondritic value and far below that of the background metal layers, suggesting differential ablation and/or rapid chemical processing of Na in fresh trails. Na trails were systematically broader than K trails (median FWHM ratio 1.29), indicating differences in diffusion or chemical loss between the two metals. Events with higher ratios were concentrated in April and May (median 14.0, versus 7.7 in other months). We discuss these results and their implications for meteoric input to the MLT metal layers.

Speaker: Dr Femi Olajide-Owoyomi (National Institute for Space Research, INPE, Brasil.)

10:30 Coffee Break

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

35 Upward Lightning Flashes on Wind Turbines: The Risk of Multi-Point Lightning Attachment on Wind Turbines

The increasing expansion of wind power generation has highlighted the vulnerability of wind turbines (WTs) to lightning strikes, particularly upward flashes. Due to their height and blade rotation, WTs exhibit initiation and attachment processes distinct from those in static structures. This work analyzes the physical processes involved in the development of upward lightning in WTs using recordings from conventional, high-speed, and high-sensitivity cameras obtained between 2021 and 2025. The analysis reveals that WTs act as active receptors, emitting corona discharges from all blades under thunderstorm conditions. These emissions respond dynamically to environmental atmospheric discharges, with intensification being the most frequent behavior. Notably, simultaneous corona occurrence on multiple blades was identified as a precursor to complex events, such as the initiation of multiple upward flashes on different blades and the attachment of a single discharge to multiple contact points. This study contributes to a deeper understanding of WT vulnerability by detailing the dynamic physical mechanisms of upward lightning flashes.

Speaker: Dr Tagianne da Silva (INPE)

36 ORIGIN OF A PHANTOM FORBUSH DECREASE EVENT ON JANUARY 31, 2012

We investigate a Phantom Forbush Decrease event on January 31, 2012. Phantom Forbush Decreases are sudden cosmic ray depressions without clear in-situ signatures of interplanetary coronal mass ejections (ICMEs), and their origin remains poorly understood. Using multi- instrument remote-sensing, in-situ, and ground-based data, six preceding CMEs are identified,including two fast full-halo events. Trajectory and modeling analyses suggest a shock–shock interaction produced a large-scale merged structure that propagated toward Earth, explaining the observed cosmic ray decrease despite the absence of a detectable ICME. These findings provide new insight into the origin of Phantom Forbush Decreases and the role of complex heliospheric disturbances.

Speaker: Jesus Alberto Nunez (National Institute for Space Research)

37 Aerosol-Radiation Interaction: Impacts on Atmospheric Stability and Lightning activity.

This research investigates the impact of aerosol-solar radiation interaction on atmospheric stability and lightning activity in the Metropolitan Region of São Paulo (RMSP). Literature provides evidence of a boomerang-shaped behavior in lightning activity due to increasing aerosol concentrations. While aerosols influence clouds through both microphysical (indirect) and radiative (direct) effects, this study focuses mainly on the direct effect, where aerosol scattering and absorption generate a cooling effect in the lower troposphere.
To elucidate the mechanisms behind this effect, the research methodology has evolved from a purely observational approach to the integration of numerical modeling. Previously, in master’s research, a range of 5 years of clear-sky data were analyzed to isolate the radiative interactions without cloud coverage interference. PM10 concentration data from CETESB were utilized alongside lightning observations from GLM and ENTLN, while the Clarity Index (Kt) and ASHRAE model were employed to quantify atmospheric transparency. The observational baseline demonstrated a clear boomerang-shaped trend: lightning activity increases proportionally with PM10 up to a threshold of 60 µg/m³, beyond which severe solar radiation attenuation occurs, increasing atmospheric stability and suppressing subsequent lightning.
Currently, the research seeks to demonstrate that the aerosol-solar radiation interaction stabilizes the lower troposphere and suppresses the lightning activity. To physically quantify this stability suppression and expand upon the observational findings, the current methodological framework incorporates the CATT-BRAMS system as a primary data source. By extracting vertical thermodynamic profiles and atmospheric stability indices from the model outputs, it becomes possible to dynamically isolate the direct radiative forcing. This presentation discusses this methodological evolution, detailing how the integration of surface observations, satellite data, and structured numerical datasets allows for a deeper understanding of the physical mechanisms driving aerosol-induced atmospheric stabilization.

Speaker: Abdala Elias Nader (INPE)

38 Cosmic Ray Muon Forbush Decrease and Its Relation with ICMEs

Muons are secondary particles formed by the interaction of a primary Galactic Cosmic Ray with the Earth's atmosphere, whose primary proton is influenced by a solar magnetic structure that travels throughout the heliosphere. This interaction between the primary proton and solar structures is known as Heliospheric Modulation of cosmic rays. The solar structures that cause the most intense cosmic ray modulation are the Interplanetary Coronal Mass Ejections (ICMEs), whose magnetic structure called Magnetic Cloud, have a helical magnetic field, which hinders the entry of cosmic rays inside the ICME, causing a decrease on the cosmic ray observations when this structure intercepts the Earth. The Forbush Diminution of cosmic rays was first linked to solar structure by S. E. Forbush in 1937, who had this phenomenon named in his honor for his discovery. In this sense, a detailed analysis of cosmic ray Forbush decrease observed by muon detectors on the Earth's surface is necessary to understand whether the polarity of the helical structure of the magnetic cloud plays an important role in the size of the decay and its recovery time.

Speaker: Marlos Rockenbach (INPE)

39 A Resposta da Multifractalidade de Uma Nuvem Magnética durante um evento de ICME.

O método MultiFractal Detrended Fluctuations Analysis (MFDFA) tem sido amplamente utilizado e aplicado em várias áreas tais como Medicina, Economia, Física, Ciências Atmosféricas e etc. para estudar a multifractalidade de séries temporais. Em âmbito de ciências espaciais, estudos anteriores constataram que lâminas de corrente poderiam originar a multifractalidade do vento solar. Mas quando tal análise foi reproduzida para um evento de ICME, pode-se constatar que lâminas de corrente contribuem para a multifractalidade, mas devido a complexidade dos eventos de ICME, onde é possivel se observar turbulência bem desenvolvida, lâminas de corrente, além conjunto de estruturas coerentes, de transição de fase, interações, cujas as naturezas diferentes fontes de multifractalidade. No presnete trabalho investigaremos as diferentes fontes de multifractalidade que podem surgir numa magnetic cloud durante uma ICME.

Speaker: Alexandre Sacata

12:00 Lunch

Invited Talk | Palestra Convidada

Conveners: Karen Julia Coldebella Ferreira (National Institute for Space Research (INPE) / NASA Goddard Space Flight Center), Jaziel Campelo (Instituto Nacional de Pesquisas Espaciais)

40 Pesquisas em Dinâmica e Química da Média Atmosfera no INPE

A região da atmosfera compreendida entre aproximadamente 20 e 110 quilômetros de altitude é conhecida como média atmosfera. Esta região fica acima da troposfera e baixa estratosfera, onde os eventos meteorológicos ocorrem e abaixo da termosfera que é altamente afetada pela variabilidade solar. Imerso nesta região é de especial interesse a região entre 80 e 110 quilômetros de altura, comumente designada como alta mesosfera e baixa termosfera (MLT em inglês). Esta região desperta a atenção devido à fenômenos peculiares que aí ocorrem, como o aparecimento de camada estreitas de emissão aeroluminescentes (Airglow), de camadas de metais originados da queima de meteoros e início das regiões de fraca ionização (região D e base da região E da ionosfera). Estes fenômenos podem ser estudados por medidas feitas no solo através de radares na faixa ótica e de rádio. O INPE tem estudado esta região desde os anos 1970 utilizando medidas passivas como o airglow e ativas como o Radar de Laser. Mais tarde, a partir de 1999 também passou a medir ventos e temperatura na região MLT com radares Meteóricos. Nesta palestra descreveremos brevemente estes dois instrumentos, os resultados apresentados ao longo dos anos e as perspectivas futuras.

Speakers: Prof. Paulo Batista (INPE), Prof. Paulo Prado Batista (INPE)

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

Conveners: Karen Julia Coldebella Ferreira (National Institute for Space Research (INPE) / NASA Goddard Space Flight Center), Jaziel Campelo (Instituto Nacional de Pesquisas Espaciais)

41 MHD global magnetospheric simulations during the Laschamps excursion of the geomagnetic field.

During the Laschamps excursion, Earth’s geomagnetic field deviated strongly from its usual dipolar structure, possibly creating a magnetosphere markedly different from today’s. Using global MHD simulations driven by a solar coronal mass ejection, this study starts the comparison of the modern IGRF field with a reconstructed Laschamps configuration to examine changes in plasma regions, current systems, and reconnection sites. Therefore, the presentation will begin the discussion of the emerging comparison framework and its possible implications for geospace conditions during geomagnetic excursions or polarization changes.

Speaker: Carlos Eduardo Quintanilha (INPE)

42 Development of a Thermo-Optic Mach–Zehnder Interferometer for Solar Radiometric Instrumentation

Accurate temperature monitoring is essential in a wide range of scientific and technological applications, particularly in systems whose performance is sensitive to thermal variations. In thermal radiometry, temperature measurement can play a central role in the determination of the absorbed radiant power. In electrical substitution radiometers, for example, the heating produced by incident radiation is compared with that produced by an equivalent electrical power, making precise temperature sensing a fundamental element of the measurement process. In this context, thermo-optic sensors are attractive because they can provide compact integration, optical readout, and potentially fast response times. These characteristics make integrated thermo-optic devices promising candidates for solar radiometric instrumentation. This work presents the development and fabrication of an integrated thermo-optic sensor based on a Mach–Zehnder Interferometer (MZI). The proposed device consists of Ta₂O₅-core pedestal waveguides fabricated on a silicon substrate. Its operating principle is based on the temperature dependence of the optical properties of the waveguide material. Temperature variations modify the effective refractive index and, consequently, the optical path length of the interferometer arms. The resulting phase difference between the two arms changes the interference condition at the MZI output, providing a mechanism for converting temperature variations into measurable changes in optical intensity. The fabrication of the proposed structures demonstrates the technological feasibility of implementing MZI-based thermo-optic devices using Ta₂O₅ pedestal waveguides. The fabricated devices represent an initial step toward the development of compact integrated temperature sensors for radiometric instrumentation. Further work is required to integrate the thermo-optic device with the other components of the radiometric system and to evaluate its operation as part of a complete instrument.

Speaker: Adriany Barbosa (INPE)

43 Kinetic Theory of Electrons in the Young Solar Wind through Analytical Deduction of the Heat Flux of Whistler Waves

The heat flux in the solar wind is a fundamental mechanism for understanding the expansion, thermal pressure gradient, and global thermodynamics of interplanetary plasma. Due to the weakly collisional nature of this medium, electrons organize themselves into distinct populations (core, halo, and strahl), with suprathermal electrons being the main conductors of thermal energy along the magnetic field lines. Whistler-mode waves play a crucial regulatory role: through wave-particle interactions, they promote pitch-angle scattering of these suprathermal electrons, limiting the free conduction of heat flow and coordinating the macroscopic evolution of the plasma. The objective of this work lies in the calculation of the heat flux mediated by whistler waves, adopting an analytical approach of the Kappa velocity distribution function (VDF). The use of the Kappa distribution is necessary because classical Maxwellian distributions fail to capture the quasi-equilibrium states and high-energy tails that characterize electrons in the solar wind. This development overcomes limitations and noise inherent in strictly numerical approximations, providing a detailed basis for evaluating the growth rates of electron-driven instabilities. This approach offers the necessary support for interpreting and validating the complex in-situ measurements of particle distributions performed by contemporary space missions.

Speaker: Laíne Soares (Instituto Nacional de Pesquisas Espaciais)

44 Identifying Satellite Crossings of the Earth's Magnetosheath Using Unsupervised Learning Algorithms

In this study, we applied machine learning techniques to perform an unsupervised clustering of THEMIS satellite orbits to detect magnetosheath crossings. We used the DBSCAN algorithm to analyze crossings within a range of less than 40 Earth radii, focusing on data from the THEMIS-B (THB) and THEMIS-C (THC) spacecraft during 2008 and 2009. These spacecraft were selected due to their eccentric orbits, which facilitate multiple crossings through the magnetosheath. Using electron, ion, and magnetic field data, our algorithm effectively identified several magnetosheath crossings, demonstrating the robustness and applicability of the unsupervised approach. As a final result, we created a consolidated database compiling the magnetosheath crossings identified for the THEMIS mission, which constitutes a valuable resource for the detailed study of magnetospheric dynamics and has the potential to contribute to the development of more accurate models of the magnetosphere in the future.

Speaker: javier silva (Instituto Nacional de Pesquisas Espaciais)

15:30 Coffee Break

Invited Talk | Palestra Convidada

45 MPPSim – Uma Plataforma Multifísica Aberta para Simulação Científica

O MPPSim é uma plataforma computacional multifísica, modular e de alto desempenho, ainda em desenvolvimento e com planos de se tornar aberta. Sua arquitetura combina uma grade canônica com vistas configuráveis e um sistema de plugins dinâmicos, permitindo que solvers de plasmas (PIC/FDTD), fluidos (FVM/SPH), meios granulares (DEM) e sólidos deformáveis (FEM) sejam acoplados de forma flexível, sem a necessidade de recompilar o núcleo. Na área de física espacial, a plataforma cobre ondas e instabilidades cinéticas de plasma (Landau, feixes, modos magnetosônicos e Alfvén), aceleração de partículas e casos clássicos de reconexão magnética como aplicações-alvo. Nas geociências, os módulos de fluido e granular dão suporte a escoamentos, transporte de contaminantes em aquíferos, migração de dunas e morfodinâmica de leitos, incluindo a segregação de minerais pesados em sedimentos costeiros. Os módulos são validados contra referências analíticas e numéricas, com exemplos de precisão como: cavidade de Ghia (Re=100) dentro de ~1%, velocidade terminal de Stokes com erro 0,00%, início de movimento pelo critério de Shields com erro 1,9% e celeridade de migração de duna (Exner) com erro 0,45%. Cada nova capacidade entra na plataforma somente após um teste de validação PASS no conjunto automatizado de regressão. Nesta apresentação, mostraremos os fundamentos da arquitetura, as capacidades dos módulos e exemplos de validação, e discutiremos como estender a plataforma a novos problemas, de instabilidades de plasma a processos sedimentares. Ao final, convidamos alunos e pesquisadores a acompanhar o desenvolvimento, propor novos plugins e usar o MPPSim como uma ponte entre a pesquisa fundamental e as aplicações em geociências e ciências espaciais.

Speaker: Dr Manilo Soares (UFRN)

Oral Presentations | Apresetações Orais

Apresentação dos Alunos

46 Investigation of Kinetic Signatures and Energy Conversion in Anti-parallel Magnetic Reconnection via the MMS Mission

Magnetic reconnection is a fundamental physical process that converts magnetic energy into plasma energy. It occurs in regions where the restructuring of field line topology and particle acceleration are enabled by the violation of the frozen-in flux condition. This work presents a detailed investigation of the microphysics of this process, focusing on the Electron Diffusion Region (EDR), utilizing high spatial and temporal resolution data from NASA’s Magnetospheric Multiscale (MMS) mission. The central objective is to analyze dayside reconnection events at the Earth's magnetopause under anti-parallel regimes, characterizing kinetic signatures and quantifying energy conversion (J.E’) by calculating the non-ideal terms of the generalized Ohm's law.The methodology is based on the use of Burst mode data collected by the FPI, EDP, and FIELDS instruments across the mission's four spacecraft, which are transformed into the local LMN coordinate system to calculate the non-ideal terms. The investigation employs the energy conversion term J.E’ to measure the effective energy transfer from the field to the plasma. It also presents a comparative statistical approach using Functional Principal Component Analysis (FPCA) among several events selected from the literature to identify global patterns in energy conversion efficiency. The results reveal two main functional components, accounting for 70.8% of the total variability of the events, which are related to the peak of energy conversion and modifications in the temporal width of the energy conversion region, respectively. The model was validated by high coefficients of determination (R² = 0.979 for predicting the conversion peak and R² = 0.808 for the total converted energy). It is concluded that reconnection dynamics depend not only on the magnitude of the converted energy but also on the temporal organization of dissipation during the EDR crossing, demonstrating the effectiveness of functional techniques in the statistical characterization of magnetic reconnection phenomena.

Speaker: Cecilia Sa (INPE)

Thursday 8 October

Visitas

Convener: Jose Marchezi (National Institute for Space Research - INPE)

Visitas

Friday 9 October

Oficinas: Avaliação do Planejamento Estratégico PG-GES

Convener: Alisson Dal Lago (INPE - National Institute for Space Research)

12:00 Almoço | Lunch

Formatura

Convener: Femi Olajide-Owoyomi (INPE)

Invited Talk | Palestra Convidada: Encerramento

Happy Hour